You should not be using apt-get update, and generally be Very careful around apt-get on LMCE 0710. The GUI version (Adept, etc) were disabled for a reason. There are lots of critical dependencies on the specific release versions of various LMCE modules/packages, updating them will irreparably damage your system. Please don't go hacking around until you understand the consequences of some of these steps! There really should be any need to do an update....